Inclusion Criteria: Medication Use for RA patients. RA subjects taking disease modifying anti-rheumatic drugs (DMARDs) must be on a stable regime for one month before study and stable throughout study. RA subjects using DMARDs will be categorized as follows: 1) no DMARDs; 2) DMARD monotherapy with sulfasalazine, hydroxychloroquine, minocycline, or azothioprine, 3) DMARD monotherapy with methotrexate or leflunomide, 4) biologic therapy with or without concomitant DMARDs.